Investigation of nonisothermal two-dimensional filtration in multylayer reservoir

Abstract

The problem of an unsteady temperature field during two-dimensional fluid filtration in a multilayer reservoir is investigated taking into account the barothermal effect, radial and vertical permeability inhomogeneities. The results of comparing the analytical and numerical calculations of the temperature changes of the fluid flowing from the reservoir for two various models of reservoir heterogeneity are presented. From the obtained results it follows that 1. The presence of radial inhomogeneity of permeability in the near-well zone of the layered formation leads to fluid flows between the layers, which affects the temperature change rate of the liquid flowing from individual layers. 2. Non-stationary temperature profiles over the thickness of the layered formation at low inflow times contain information about the flows between the layers due to radial inhomogeneity in the near-well zone of the formation. 3. Flows between layers lead to large errors in solving the inverse problem of estimating the distribution of permeability in the reservoir based on non-stationary temperature data. 4. The presence of flows between the layers does not exclude the possibility of estimating the radius of the contamination zone. 5. To correctly account for the influence of flows between layers when calculating the nonstationary temperature in a layered formation with a disturbed near-well zone, it is necessary either to use a two-dimensional numerical model of non-isothermal filtration or to change the algorithm for correcting the layer’s flow rate for short and long inflow times in the onedimensional analytical model.